Portable carts for transporting oxygen and fuel gas cylinders are common place and widely used where welding and metal cutting operations take place. These portable carts typically have wheels to facilitate movement of the cart and hold two compressed gas cylinders side by side in an upright position with their valves uppermost. One of the cylinders contains oxygen and the other cylinder contains fuel gas, such as acetylene or propane. The cylinders are secured to the portable cart by a chain or bracket. While in operation and between uses, the oxygen and fuel gas cylinders are routinely stored on the portable cart with regulators and hoses still attached to the cylinder valves.
Although their use is indispensable for welding and metal cutting operations, use and storage of oxygen and fuel cylinders in near proximity to one another poses a particular danger. Should fuel gas, from a leak or unintentional release, ignite in near proximity to an oxygen cylinder, the heat released from the burning fuel gas can cause the pressure in the oxygen cylinder to rise. In the event that the rising pressure in the oxygen cylinder activates the pressure relief valve in the cylinder valve, oxygen gas would be released enriching the surrounding air and intensifying the fuel gas flame with potential catastrophic results. Because of the particular danger posed in the use and storage of oxygen and fuel gas cylinders in near proximity to one another, the United States Department of Labor, Occupational Safety & Health Administration has promulgated regulations for the use and storage of oxygen and fuel gas cylinders. Of particular relevance, title 29 Code of Federal Regulations section 1926.350(a) (10) provides that “Oxygen cylinders in storage shall be separated from fuel-gas cylinders or combustible materials (especially oil or grease), a minimum distance of 20 feet (6.1 m) or by a noncombustible barrier at least 5 feet high having a fire-resistance rating of at least one-half hour.” The National Fire Protection Association has also recognized and addressed, in its regulations, the danger posed by storage of oxygen and fuel gas cylinders in near proximity to one another. The National Fire Protection Association regulations like the United States Department of Labor, Occupational Safety & Health Administration regulations require a 20 foot separation or 5 foot barrier of noncombustible material between oxygen and fuel gas cylinders; additionally, where a barrier of non-combustible material is used, the National Fire Protection Safety regulation 51 2-4.2 prescribes that “The barrier shall interrupt all lines of sight between oxygen and fuel-gas cylinders within 20 ft. of each other.”
Attempts have been made in the prior art to construct portable carts, used in welding and metal cutting operations, that can safely store oxygen and fuel gas cylinders adjacent to one another on portable carts; these prior art attempts have met with limited success. In one attempt to provide a portable cart, upon which adjacent oxygen and fuel gas cylinders could be stored, a five foot tall ¼ inch thick steel plate was interposed as a barrier between the oxygen and fuel-gas cylinders. The United States Department of Labor, Occupational Safety & Health Administration found, in a letter opinion of Apr. 21, 1991, that this heavy gauge metal partition is not a compliant noncombustible barrier having a fire resistance rating of at least one half-hour.
U.S. Pat. No. 6,116,623 to Salvucci illustrates another attempt to provide a portable cart upon which adjacent oxygen and fuel gas cylinders could be stored. In the Salvucci cart, a flue constructed from metal sheet is interposed as a barrier between the oxygen and fuel-gas cylinders on the portable cart. The flue in the Salvucci cart provides a one inch wide air space between its metal sides separating the cylinders and is positioned with the lower end of the flue elevated above the platform that supports the cylinders to provide an air intake for the flue. As the lower end of the flue in the Salvucci cart is elevated above the cylinder support platform, the flue of the Salvucci cart does not provide a complete and uninterrupted barrier between the entire height of the oxygen and fuel gas cylinders.
Accordingly, it is an objective of the present invention to provide a portable cart for the use and storage of adjacent oxygen and fuel gas cylinders that provides a complete and uninterrupted noncombustible heat and fire resistant barrier separating the oxygen cylinder from the fuel-gas cylinder.